Existing computer systems have numerous input devices. The most common input device is a standard keyboard. The standard keyboard comprises, at a minimum, four rows of keys with ten keys in each row. It is common practice that the four keys on each end of the next to the last row are home keys for the fingers of an operator. The operator's thumbs are used to actuate a space bar which may be considered as a fifth row. Another common computer input device is the mouse. The mouse includes a housing with a rotatable ball on the base of the housing. The ball is moved over a mouse pad. The top cover of the mouse has one or more buttons. In operation, the mouse is used to acquire control over the cursor on the display of a computer. The mouse includes an arrow display or mouse pointer. By moving the mouse pointer to any point on the display and actuating the mouse button one time, the display cursor is automatically moved to the position indicated by the mouse pointer. The mouse has other functions. If the mouse pointer is disposed over one or more graphical user interfaces that appear on display, the function indicated by the graphical user interface may be selected by clicking on the mouse. Still another function of the mouse is to select portions of the display for further operation. In a typical word processing operation, the mouse is positioned at the start of a text to be selected, a mouse button is held down; and then the mouse pointer is dragged over selected text. With the text selected, further functions may be performed on that text by entering commands from the keyboard or making further use of the graphical user interface with or without the mouse. For example, the text may be underlined, copied, set in a different font, etc.
There are other input devices that are somewhat similar in operation to the mouse. These devices include track balls, touch pads, and joy sticks. Joy sticks are more commonly used in connection with computer games since they normally require two hands for operation of all the joy stick controls. Some laptop computers have used small joy sticks located in the keyboard for controlling a pointer. Other input devices include track balls and touch pads. Track balls work similar to a mouse except the ball is disposed separate from the keyboard or fixed to one side and it is moveable by one or more fingers of the operator. Touch pads are also attached to either one side or the bottom of the keyboard or provided as separate input devices like the mouse. Touch pads provide an input system that is readily learnable by most operators. One advantage of the touch pad is that it uses an intuitive ability to point with one's index finger to a desired item.